CSharpCodeBlock - [0..22)::22 - [@val?[abc]?.more?[def]]
    CSharpImplicitExpression - [0..22)::22
        CSharpTransition - [0..1)::1 - Gen<None> - SpanEditHandler;Accepts:None
            Transition;[@];
        CSharpImplicitExpressionBody - [1..22)::21
            CSharpCodeBlock - [1..22)::21
                CSharpExpressionLiteral - [1..22)::21 - [val?[abc]?.more?[def]] - Gen<Expr> - ImplicitExpressionEditHandler;Accepts:NonWhitespace;ImplicitExpression[RTD];K14
                    Identifier;[val];
                    QuestionMark;[?];
                    LeftBracket;[[];
                    Identifier;[abc];
                    RightBracket;[]];
                    QuestionMark;[?];
                    Dot;[.];
                    Identifier;[more];
                    QuestionMark;[?];
                    LeftBracket;[[];
                    Identifier;[def];
                    RightBracket;[]];
